Washington — “A lie can run around the world before the truth can get its boots on,” it is said in a quote commonly attributed to Scottish inventor James Watt.

This aphorism may never have felt more true than in the 2008 presidential campaign. And more than ever, independent organizations and media outlets – from the Annenberg Public Policy Center’s Factcheck.org to Politifact, a project by the St. Petersburg Times, to other truth-squadding efforts in the mainstream media – have tried to referee the claims and assertions of the candidates and their campaigns.

Alaska Gov. Sarah Palin, the GOP vice-presidential nominee, has stated repeatedly that she rejected the so-called “bridge to nowhere” as congressional pork, when in fact she welcomed it until it became politically radioactive in Washington. She continued to repeat her “thanks, but no thanks” line long after a wave of media stories punctured her claim.

Barack Obama, the Democratic presidential nominee, has dined out for months on how his Republican rival, John McCain, wants to wage war in Iraq for 100 more years when, in fact, Senator McCain’s point was that he was willing to maintain a US military presence in Iraq long after the hostilities had ended, as the US did in Europe after World War II.

In other words, some people are going to care deeply that, for example, Governor Palin is making questionable or untrue assertions about her record and others won’t. “It depends on your view of Sarah Palin,” says Mr. Rosenstiel.

A recent Gallup poll shows that the public’s view of media coverage of Palin depends greatly on partisan affiliation. A majority of Republicans – 54 percent – say the coverage has been unfairly negative, while only 29 percent of independents and 18 percent of Democrats feel that way. So it is through that filter that voters will assess fact-checking. And it may well be that the wave of columns and editorials in the mainstream press expressing outrage over McCain’s statements and ads about Obama will serve mainly to satisfy McCain’s opponents, while doing little to change the minds of his supporters. How undecided voters and “soft leaners” – those not firmly in one camp or the other – are affected remains unclear.

Often, such voters don’t start really focusing on the campaign until the very end.Other research indicates that attempts to correct misinformation are unlikely to change minds. In an experiment by two academics, volunteers were given a mock news article with potentially misleading information – half with a correction, half without. The researchers discovered that the group that received the correction may end up believing the misleading information more strongly after hearing the correction.

“The argument we make in the paper is that people are counterarguing in their heads,” says Brendan Nyhan, a political scientist at Duke University and one of the researchers. “They’re coming up with reasons to disagree with the factual claim, and actually convincing themselves more than they would have believed otherwise.”

Still, fact-checking is a media growth industry. The St. Petersburg Times has found a ready audience in other papers, through the use of a Web tool called Widgets, for its research. As politicians have become more aggressive about communications and spin, “the press has moved from being a color commentator in the booth to at least at times being a referee on the field,” says Rosenstiel from Project for Excellence in Journalism.

Rosenstiel and other press observers attribute the rise and speed of fact-checking in this election at least in part to the “swift boat” phenomenon in the 2004 election, in which Democratic nominee John Kerry’s Vietnam War record was eviscerated by his opponents. Still, the candidates this year have seemed lax about correcting false information. Brooks Jackson, director of Factcheck

.org, notes that the McCain campaign repeatedly asserts that Obama is going to raise taxes broadly, while the truth is that Obama’s plan would raise taxes only on those earning more than $250,000 a year while cutting taxes for 80 percent of workers and their families. Obama has not moved assertively to correct this misimpression, and polls show that majorities of middle-income voters believe that Obama would raise their taxes.

In the face of a false accusation, many politicians – including some of the most successful, such as former President Bill Clinton – will simply change the subject, and attack the opposition on something else. In 1993, when Mr. Clinton was accused of signing the “largest tax increase in history,” he didn’t counter with, “well, in fact, it was the 12th or 13th largest increase in history.” Instead, he accused the Republicans of wanting to cut Medicare, Mr. Jackson says.